This invention relates to twist-grip shifters for bicycles in particular a twist-grip shifter having an integrated locking device that connects a housing element and an actuating element of the twist-grip shifter.
Twistshifters are widely used in bicycles of nearly all types and quality classes. The object of such twistshifters is to make it possible for the cyclist to manually select and monitor the desired gear ratio of the bicycle transmission manually in a simple, safe and ergonomic manner. Twistshifters may be used to actuate internal gear hubs or derailleurs. Twistshifters usually include a housing element mounted to the handlebar near the end of the handlebar. Such shifters also include an actuating element that is rotatable about the axis of the handlebar. Both the housing element and the actuating element are generally mounted about the handlebar in the form of a ring. The actuating element is generally provided with a non-slip outer surface made from an elastomer forming a rotatable grip, typically positioned adjacent a stationary grip, both grips located on the handlebar. However, the actuating element of the twistshifter may form the entire handlebar grip.
For safety reasons, the actuating element is secured against undesirable axial movements along the handlebar axis. An actuating element of a twistshifter that is not or inadequately secured against axial movements might otherwise slip off from the end of the handlebar as a consequence of the arm forces transferred to the handlebar via the handlebar grips during cycling, potentially causing dangerous falls. Therefore, it is important to secure the actuating element axially on the handlebar or to the housing element of the twist-grip shifter in an effective and stable manner.
A twistshifter for bicycles is known from German Patent Application 199 15 333 A1 in which the actuating element is axially secured relative to the housing element of the twistshifter by an additional annular locking element positioned at the outer end of the twistshifter, the locking element being provided with a bayonet lock or a snap connection. The manufacture and installation of the locking element, the housing element, and actuating element of the twistshifter and in addition to the necessary complementary-shaped companion parts to be joined to the housing element, is expensive and time-consuming. Moreover, the tools for manufacturing the parts are complex and also expensive. In addition, the discrete locking element may be lost or forgotten during assembly or installation of the twistshifter, resulting in a temporarily functional twistshifter, but one under risk of having the actuating element slide off the handlebar end during use.